High-fluorescent product of folic acid photodegradation: Optical properties and cell effect

Abstract

Folic acid (FA) is a natural body component essential for normal cell growth and division. Uptake of FA into cells is mediated by the folate receptors with particularly large amount of folate receptors found on the surface of cancer cells. This feature traditionally is used for selective drug delivery systems targeting in cancer cells or visualization of the border between healthy and tumor tissue based on FA-modified fluorescent labels. However, preparation of FA-conjugates can be an elaborate procedure, while FA itself shows low photostability under illumination. Here we use photodegradation of FA colloid to produce high fluorescent product and compare its effects on the cells grows and division with the ones of FA. It was found UV-irradiation of FA colloid for 60 min allows obtaining water soluble fluorophore with quantum yield 30 ± 2 %. We also show that the resulting fluorescent product retained FA biological activity in relation to cell growth and division, comparable to native FA.